Field of the Invention
The present invention relates to an organic light emitting diode (OLED) display device, and more particularly, to an OLED display device and a driving method thereof that can efficiently compensate for deterioration of an organic light emitting diode.
Discussion of the Related Art
Recently, flat panel display devices having excellent properties, such as a thin profile, low weight, low power consumption and the like, have been developed and applied to various fields.
Among the flat panel display devices, an organic light emitting diode (OLED) display device emits light by combining electrons and holes in a light emitting layer.
Typically, the OLED display device can be formed on a flexible substrate, has a high contrast ratio because it is a self-luminous type device, displays moving images easily because its response time is several micro-seconds, has no limit to viewing angles, and is stable at low temperatures. Further, because the OLED display device can operate with a relatively low voltage of DC 5V to 15V, it may be easy to fabricate and design a driving circuit.
However, the OLED display device can have a problem in that due to the characteristics of the OLED, the property of the OLED changes over time and may deteriorate. For example, when a fixed pattern image is displayed for a long time, deterioration of the OLED in the displayed portion may be accelerated. This may cause an afterimage to occur in the deteriorated portion, thereby degrading the display quality.
As a solution to prevent the deterioration, a method to reduce a brightness for the fixed pattern image portion has been suggested. This method may be confined to only deterioration prevention, and may not compensate for actual deterioration of the OLED when it occurs.
As a solution to compensate for the deterioration, a method may be provided where an OLED is directly sensed to detect a deterioration, and a compensation data is generated using a LUT (look-up table) produced through deterioration experiments. However, this direct sensing compensation method may need a large amount of LUT data, and thus a compensation time may be long. Furthermore, complexity of the compensation algorithm may be high, and thus a size of a logic circuit may increase as well as the cost of the compensation circuit.